[Special aspects of individual oral hygiene in patients with I class gingival recession]. / Osobennosti individual'noi gigieny rta u patsientov s retsessiei desny I klassa.

AIM: To assess the efficacy of additional oral hygiene products in patients with gingival recession. MATERIAL AND METHODS: 30 patients aged from 18 to 35 years with gingival recession participated in the study. The patients were distributed into 2 groups 15 patients in each depending on the use of brushes. The patients in the first group used manual toothbrush Curaprox CS 5460 together with single-tufted brush Curaprox CS 1006 as an additional means of oral hygiene. The patients in the second (control) group used only manual toothbrush Curaprox CS 5460. RESULTS: No significant differences in the values of Silness-Löe and Navy-Rustogi indixes between groups were found at initial examination (p=0.713). However, the values of these hygienic indexes were significantly lower in the first group compared to the control group after 1 week and 1 month of the study (p<0.001). It was shown that oral hygiene in patients with gingival recession was significantly better in case of use of single-tufted brush. CONCLUSION: Maximal efficacy of oral hygiene in patients with gingival grade 1 recession can be achieved by using manual toothbrush Curaprox CS 5460 together with single-tufted brush Curaprox CS 1006.

The accuracy of CBCT for the detection and diagnosis of vertical root fractures in vivo.

AIM: To compare the in vivo accuracy of CBCT for the detection of fracture lines versus the diagnosis of vertical root fractures (VRFs) according to characteristic patterns of associated bone resorption. METHODOLOGY: Eighty-eight patients with symptoms typical of VRFs in root filled teeth, who underwent a CBCT examination and later had the teeth extracted, were divided into two groups: the fracture group (n = 65) and the control group (n = 23). Five blinded observers assessed the CBCT images in two sessions. During the first session, they were asked to state the diagnosis according to the CBCT and clinical data. During the second session after 2 weeks, they assessed only axial slices and were asked to detect a fracture line. The mean CBCT specificity, sensitivity, accuracy values and area under the receiver operating characteristic (AUROC) curve were calculated and compared using the Wilcoxon signed-rank test. RESULTS: The average sensitivity of CBCT for the diagnosis of VRFs was 0.84 ± 0.2. The accuracy and AUC values were 0.81 ± 0.08 and 0.84 ± 0.17, respectively. The sensitivity, accuracy and AUC values for the detection of VRFs were significantly lower: 0.17 ± 0.24 (P = 0.042), 0.54 ± 0.07 (P = 0.043), and 0.52 ± 0.09 (P = 0.043), respectively. The specificity of CBCT for the detection and diagnosis of VRFs did not differ significantly (P = 0.50). CONCLUSION: Cone-beam computed tomography was helpful in VRF diagnosis even when it was not possible to visualize the fracture line.

[The in vitro examination of the effectiveness of antiseptic substances for a surface disinfection of teeth inoculated with Escherichia coli]. / Issledovanie in vitro éffektivnosti antisepticheskikh veshchestv dlia poverkhnostnoi dezinfektsii zubov, inokulirovannykh Escherichia coli.

The aim of the study was to assess the possibility of penetration of Escherichia coli bacteria into the dentinal tubules of the samples and determine the antimicrobial efficacy after 5 and 20 min exposition of 3% H2O2 (groups I and II) and 1 and 5 min exposition of 3% NaOCl (groups III and IV) for surface disinfection of bovine teeth. The samples were subjected to inoculation with E. coli suspension. The quality of disinfection was assessed with the three methods. The surface disinfection of samples proved to be effective only in groups II and IV. In the cultures of all dissolutions of dentinal chips suspensions in groups I, III and V there was a growth of E. coli in the form of a continuous pitch. In the group II a growth of Escherichia coli was revealed only in the initial dissolution in the quantity 1,8x101 CFU/ml, whereas in the group IV the growth was nil. Quantitative estimation of bacterial penetration using the method of maximum dissolutions revealed similar quantity of bacteria as in the group II as well as in the calculation of CFU. The application of 3% solution of H2O2 with the exposition of 20 minutes secures the qualitative surface disinfection of teeth without destruction of bacteria inside dental tubules and that allows to discover viable bacteria inside dentinal tubules.

[The resistance of teeth to vertical root fractures after mechanical preparation and irrigation of root canal (pilot study)].

UNLABELLED: The aim of the study was to assess the influence of external root anatomy, time of irrigation and the rate of mechanical enlargement of root canals on root fracture resistance. Thirty six bovine teeth were decoronated and divided into 2 groups: with round and oval forms of axial root slices. The root canals were mechanically enlarged according to standard protocol and prepared for post placement. Individual cast posts were made for each tooth, the diameter of posts comprised 1/2 or 1/3 of the root diameter in different subgroups. After mechanical enlargement, the canals were irrigated with 3% sodium hypochlorite for 10 or 60 minutes in different subgroups. The teeth with posts were subjected to static vertical load by universal testing machine with the speed of 1 mm per minute. The load that had led to fracture initiation was noted. Analysis of variances was used to assess the statistical significance of the RESULTS: No statistically significant differences were found between the groups with different protocols of mechanical preparation and irrigation. Teeth with round axial root slice were significantly less susceptible to fractures than ones with oval shape of axial root slice taking into consideration the protocols of mechanical preparation and irrigation.

[Risk factors for vertical root fractures after endodontic treatment]. / Faktory riska vozniknoveniia vertikal'nykh treshchin kornia v zubakh posle éndodonticheskogo lecheniia.

The review sought to describe the main risk factors for vertical root fracture predisposition in teeth after root canal treatment: altered mechanical characteristics of dentine due to loss of moisture and use of aggressive irrigation agents, insufficient amount of remaining dentine tissue after mechanical preparation of root canals, damage to the remaining tooth structure due to the effects of posts of different materials. According to the reviewed studies it is difficult to reveal the main factor predisposing to vertical root fractures. It is likely that in each case there is an interaction of several factors.

Detection of artificially induced vertical root fractures of different widths by cone beam computed tomography in vitro and in vivo.

AIMS: To compare the diagnostic accuracy of cone beam computed tomography (CBCT) for the detection of artificially induced vertical root fractures (VRFs) of different widths in vitro and in vivo. METHODOLOGY: Vertical root fractures were induced in 25 extracted nonendodontically treated single-rooted human teeth (maxillary first premolars, maxillary canines and mandibular incisors). Twenty teeth without VRFs served as a control group. CBCT scanning (3D Accuitomo 170) was performed in vitro and in vivo. For the in vivo scanning, teeth were autoclaved, embedded into bite plates, placed in sterile plastic bags and then inserted into the mouths of volunteers. Teeth with VRFs were sectioned into axial slices and examined using a stereomicroscope to measure the widths of the VRFs. Five observers assessed the presence of VRFs using axial CBCT. Values for sensitivity, specificity, accuracy and interexaminer agreement were calculated. RESULTS: The accuracy, specificity and sensitivity of CBCT were significantly higher in vitro than in vivo for VRFs with widths 50-150 µm (P < 0.05). The sensitivity and accuracy of CBCT were significantly higher for the detection of VRFs with widths greater than 150 µm in vivo and in vitro (P < 0.05). The accuracy of CBCT in vivo was 0.29 and 0.8 for fracture widths ranging from 50 to 150 µm and wider than 150 µm, respectively. No significant differences in CBCT specificity were found between VRF widths both in vitro and in vivo. The interexaminer reliability of the raters revealed a kappa value of 0.72, demonstrating substantial agreement. CONCLUSION: The detectability of VRFs by CBCT in vitro and in vivo was dependent upon fracture width. The accuracy of CBCT in detecting VRFs of 50-300 µm width in vivo was significantly lower compared to the in vitro accuracy.

Leishmania infantum: Lipophosphoglycan intraspecific variation and interaction with vertebrate and invertebrate hosts.

Interspecies variations in lipophosphoglycan (LPG) have been the focus of intense study over the years due its role in specificity during sand fly-Leishmania interaction. This cell surface glycoconjugate is highly polymorphic among species with variations in sugars that branch off the conserved Gal(ß1,4)Man(α1)-PO(4) backbone of repeat units. However, the degree of intraspecies polymorphism in LPG of Leishmania infantum (syn. Leishmania chagasi) is not known. In this study, intraspecific variation in the repeat units of LPG was evaluated in 16 strains of L. infantum from Brazil, France, Algeria and Tunisia. The structural polymorphism in the L. infantum LPG repeat units was relatively slight and consisted of three types: type I does not have side chains; type II has one ß-glucose residue that branches off the disaccharide-phosphate repeat units and type III has up to three glucose residues (oligo-glucosylated). The significance of these modifications was investigated during in vivo interaction of L. infantum with Lutzomyia longipalpis, and in vitro interaction of the parasites and respective LPGs with murine macrophages. There were no consequential differences in the parasite densities in sand fly midguts infected with Leishmania strains exhibiting type I, II and III LPGs. However, higher nitric oxide production was observed in macrophages exposed to glucosylated type II LPG.

Structure, functions, and biosynthesis of glycoconjugates of Leishmania spp. cell surface.

Cell surface of leishmaniasis causal agent, a parasitic member of Protozoa of Leishmania genus, is covered by thick glycocalix consisting of various phosphatidylinositol-anchored molecules. This review deals with the structure and biosynthesis of the main phosphoglycans and glycoproteins of Leishmania cell surface, many of which incorporate the rare natural D-arabinopyranose, and the problem concerning the involvement of these molecules in support of Leishmania survival during their intricate life cycle is discussed.

D-Arabinose Methabolism: Characterization of Bifunctional Arabinokinase/Pyrophosphorylase of Leishmania major.

In this work we describe an unusual enzyme from Leishmania major (Arabinokinase/Pyrophosphorylase) that catalyzes the synthesis of GDP-D-arabinopyranose (GDP-D-Arap) via a D-arabinose-1-phosphate intermediate in the presence of ATP and GTP. Our data indicate GDP-D-Arap transport in vivo by the LPG2 multispecific nucleotide sugar transporter into the Leishmania Golgi apparatus, in which it can be used by glycosyltransferases as a donor substrate for glycosylation.

Generation of powerful subnanosecond microwave pulses by intense electron bunches moving in a periodic backward wave structure in the superradiative regime.

Experimental results of the observation of coherent stimulated radiation from subnanosecond electron bunches moving through a periodic waveguide and interacting with a backward propagating wave are presented. The subnanosecond microwave pulses in Ka and W bands were generated with repetition frequencies of up to 25 Hz. The mechanism of microwave pulse generation was associated with self-bunching, and the mutual influence of different parts of the electron pulse due to slippage of the wave with respect to the electrons; this can be interpreted as superradiance. The illumination of a panel of neon bulbs resulted in a finely structured pattern corresponding to the excitation of the TM01 mode. Observation of rf breakdown of ambient air, as well as direct measurements by hot-carrier germanium detectors, leads to an estimate of the absolute peak power as high as 60 MW for the 300-ps pulses at 38 GHz. These results are compared with numerical simulations. The initial observation of 75-GHz, 10-15-MW radiation pulses with a duration of less than 150 ps is also reported.